Yes your PRTD approval would likely be seen as a liability. You would need to have guardians in place. Also a risk because your parents could complain that you had been illegally taken out of the country.
Your sister likely had a PR card that wasn't expired and she got lucky if she hadn't met her residency obligation.
I see so the most logical thing would be to try for guardianship. I was also looking at other options like sponsorship? Would it be possible for my sister to sponsor me?
Yes actually I just realized how silly I was. She definitely had a valid PR card at the time.